An electric steering system of a motor vehicle generally comprises an electromechanical actuator located on the steering column or on the lower assembly which comprises mechanical members designed to provide the angular positioning of the drive wheels of the vehicle. The electromechanical actuator comprises a rotating electric motor, the shaft thereof being supported by at least one ball bearing device with four points of contact, directly or via a ball screw system.
The rolling bearing generally comprises an inner race, an outer race, each race being provided with two bearing tracks, and a set of rolling elements, generally balls, arranged between the four bearing tracks of the races.
FR 2 921 451 discloses cages for retaining balls for rolling bearings made of synthetic material, comprising sockets for housing the balls. The sockets are separated by claws arranged in pairs, opposite a shoulder. Such retaining cages are entirely satisfactory in many applications. However, in applications at low rotational speed or where the rotational direction changes abruptly, this type of cage causes various problems. More specifically, when the balls are under load, the cage is severely deformed and comes into contact with the inner race, which causes the damage thereof or even the destruction thereof.
Moreover, when changing the direction of the load applied to the rolling bearing, such as for example when steering the wheels of a vehicle provided with an electric steering system, as described above, when the driver performs manoeuvres to the left and to the right in order to park the vehicle, the cage is also severely deformed, or even destroyed.
The object of the present invention, therefore, is to remedy said drawbacks.